A breccia composed of volcanic rock fragments
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Tag: <span>A</span>
Materials sliding inwards or moving concavely inside of a break
A geophysical survey performed with a magnetometer aboard, or towed behind, an aircraft
An instrument aboard, or attached to, an airplane used to detect the strength of a magnetic field
A sodium-ferric monoclinic iron silicate, NaFe3+Si2O6, which occurs in soda-rich igneous rock
A horizontal opening driven into a hill or mountain for providing access to minerals
Having a diamond-like luster, and or hardness
Places in a mine that are ventilated and regularly inspected
A cavity or vesicle formed by the presence of trapped gas, in igneous rock, that is filled with such secondary minerals as calcite, quartz, chalcedony, or zeolites
Two or more metals together in a compound